Afterglow, made

The concept

The cosmic microwave background is a photograph of the entire sky taken when the universe was 3,000 kelvin and 380,000 years old — the instant it cooled enough to turn transparent. AFTERGLOW renders that surface as a Mollweide-projected temperature field: the whole celestial sphere flattened into one ellipse, false-coloured so its one-part-in-100,000 ripples become visible. The field drifts and resolves so that at rest it reads as a finished, living map rather than a static image — deep time you can watch settle.

Palette — argued from the physics

The false-colour ramp runs #0C1436 → #1A2A6C → #6E3A6A → #E24B2E → #F2C84B — cold navy through a violet transition to hot red and a yellow peak, the standard "blue is cold, red is hot" reading with a passage through violet that keeps midtones from muddying. Following the collection's ink/line split, the bright accent is spent only on lines and marks; all text sits on the ecru token with a scrim behind anything over the field.

Type

Space Grotesk's slightly technical, astronomical-instrument feel suits a subject that is equal parts cosmology and data. It is set light and large for the wordmark with the second syllable lit in the thermal gradient. Every number — temperature, redshift, multipole, age — is Space Mono, so the page reads like a readout panel from a telescope's control room.

Techniques

The all-sky is a single raw-WebGL fragment shader drawn over one fullscreen triangle — no three.js, no textures, no raster assets. For every pixel:

• An ellipse test masks the Mollweide map; pixels outside become deep-space void with a faint warm rim glow.
• Inside, the inverse Mollweide projection turns the pixel into a latitude and longitude, then a unit direction on the celestial sphere — so there is no seam and no pole pinching in the noise.
• That direction samples six octaves of 3D value-noise fBm. The higher octaves fade in over the first six seconds (the u_resolve ramp), so the map arrives soft and sharpens into fine structure — the "resolve".
• A very slow rotY of the sampling direction plus a drift on the noise's time axis keeps the field alive forever without ever looking busy.
• The noise value is mapped through the five-stop false-colour palette, then limb-darkened toward the ellipse edge, overlaid with a faint 30° graticule, and finished with a thin peak-yellow rim line.

Beside it, the angular power spectrum is inline SVG: the CMB TT curve with the first acoustic peak marked at ℓ ≈ 220, stroked in the same cold-to-peak gradient. It is the second-read reward — the map shows you the ripples; the sidecar shows you they are music.

Hardening: devicePixelRatio is capped at 2, the canvas resizes to its container, the rAF loop pauses on document.hidden, WebGL context loss and compile failure both fall back to a CSS false-colour gradient ellipse, and prefers-reduced-motion renders one settled static frame instead of animating.

Iteration log